The present invention relates to improvements in screen printing presses.
In screen printing presses of the type in which sheet stock is advanced through a printing station between a reciprocating print cylinder and printing screen, frequently it is necessary to make a variety of adjustments with respect to the registration of the paper, squeegee or other components when setting up the press for printing a run. Likewise, it is frequently necessary to clean or otherwise maintain or repair the printing press in the immediate printing area.
In existing screen printing presses, if adjustments or maintenance is necessary during a printing run or when initially setting up the press for a run, it is necessary to remove the printing screen frame from the screen frame cariage to obtain necessary access to the components requiring adjustment. Also with conventional presses, the squeegee and flow coater mechanism which is positioned immediately above the printing cylinder typically obstructs access to the print cylinder area where registration adjustments must be made or other maintenance or repairs performed.
Thus, with conventional screen presses, frequently the entire flow coater and squeegee mechanism and printing screen frame must be removed before or during a printing run to make relatively minor adjustments. This can greatly increase the down time of the printing press. Additionally, if an adjustment or repair is required in the middle of a printing run where ink has been applied to the squeegee, flow coater and printing screen; the task can become even more burdensome and time consuming since ink must be cleaned which frequently will drip onto various components of the press during removal of the parts for completion of the repairs or adjustments.
At least a partial solution to the various problems with conventional presses has been provided by the screen press described in U.S. Pat. No. 3,120,180 issued on Feb. 4, 1964 to the present assignee. The press therein disclosed employs what has become known in the industry as a high lift squeegee and flow coater mechanism which provides structure for elevating the squeegee and flow coater assembly upwardly from the printing area such that access to the registration means for the print stock or other apparatus in the printing area can be had either before or during a printing run.
Although this press represents a tremendous improvement in the screen printing art, the printing press of the present invention incorporates structure permitting even greater access for adjustments or maintenance. The present press provides a greater degree of flexibility of operation and adjustments of the components required for registration of the printing stock, the squeegee and the positioning of the screen frame.